DATA COMMUNICATION SYSTEM

PURPOSE:To attain two-way data communication in the CATV system comprising a tree shape coaxial cable network by converting an output data of a computer of a CATV center station at an RF MODEM, demodulating the data by an RF MODEM at the terminal side via a CATV network and displaying the result on the terminal device. CONSTITUTION:A signal via a CCP 21 and a MODEM 3 is inputted to a head end (amplifier modulation mixer) 6 of a CATV center station 1 from a computer 2. The head end 6 modulates the signal into a carrier frequency of the FM broadcast band and sends it to a home terminal 22 via a CATV network 7 and a drawing line 23. A data signal demodulated by the RF MODEM 5 and a data MODEM 3 is displayed on a terminal equipment 8 in the home terminal 22. On the other hand, a signal from the subscriber side is modulated into a voice band signal by the MODEM 3 from the data terminal equipment 8, modulated into a proper band in the FM broadcast incoming band of the RF MO DEM, modulated into a voice band by the RF MODEM 5 in the head end 6 of the CATV center 1 and sent to the computer 2 via the data MODEM 3 and the CCP 21.